Improvement in rotary printing-presses



2 Sheets-Sheet G. B. CUTTRELL. Rotary Printing-Presses.

Patented April 1, 1873.

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C. B. COTTRELL.

Rotary Printing-Presses.

Patentecj A rss1,1s73.

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CALVERT B. GOTTRELL, OF WESTERLY, RHODE ISLAND.

IMPROVEMENTv IN ROTARY PRlNTlNG-PRESSES.

Specification forming part of Letters Patent No. 137,347, dated April 1, 1873; application filed FebruaryB, 1873.

To all whom it may concern:

Be it known that I, CALVERT B. OoTTEELL, of Westerly, in the county of Washington and State of Rhode Island, have invented a new and useful Improvement in Rotary Printing- Presses,'of which the following is a specification:

In continuouslyrevolving cylinder printing-presses there is considerable inaccuracy m the registering of the sheets on the cylinder-that is to say, irregularity in the placing the sheets on the cylinder relatively to the type-so that the margins are not always the same width, the print is not always square with the paper, and other defects of like character are caused to such extent that for work'on which it is desired to have the register as exact as possible, particularly work in different colors, it is found necessary to use the stop-cylinder presses, which stop when the gripers take the paper to insure the taking all the sheets exactly alike, so as to register alike with the type but these stop-cylinder presses are incapable of turning off the work as fast as the continuouslyrevolving cylinder-presses in consequence of the time lost in stopping. Hence it is of greatimportance to produce a griper attachment in connection with a continuously-revolving cylinder capable of taking the paper While the cylinder is in motion and registering as correctly as the gripers of the stopcylinder presses do, which is the object of my invention. The difiiculty is owing to the high speed of the gripers when they close upon the paper, which is at rest, the gripers being on the cylinder and revolvingwith it, and the paper lying on'the table, which causes the gripers to slip a little on the paper while closing upon it and before seizing it with snfiicient force to overcome the m's inertia and set it in motion. This slippage varies with every variation of the speed of the cylinder; also, with different conditions of the paper and by other causes. I propose to overcome the difiiculty by having the gripers cease to revolve with the cylinder at or before the taking of the paper and be at rest, or nearly so, relatively to the cylinder while closing upon the paper, and also be gaged relatively to the paper at the same time by the instrumentality of a stop-gage or other device independent of the cylinder, but in such relation to the table whereon the sheets of paper are presented to the gripers that the latter will always come to the paper exactly the same irrespective of the speed of the cylinder. To this end I propose to have the gripers swing or slide or otherwise move forward on the cylinder by the instrumentality of cams, springs, or other devices just before coming to the place for taking the paper-say at the time of discharging or releasing the printed sheet-so as to gain time for a slight period of rest, and then fly back against the aforesaid gage or stop, and rest while closing upon the paper, thereby enabling them to gripe it firmly and se curely, and always in the same relation to the table before being set in motion with the cylinder again, so that all possibility of variation of the gripers to the sheets to be taken and slippage in starting the paper will be avoided.

Figure l is an end elevation of the cylinder and section of the table-frame and some of the contrivances for actuating the gripers, showing the latter in two positions--first, when swung forward and opened ready for going back against the stop-gage and closing on the paper, and, second, after going back and closing on the paper. Fig. 2 is a plan view with part of the table broken out and Fig. 3 is a section and elevation on an enlarged scale, showing the gripers the same as in the first position of Fig. 1.

Similar letters of reference indicate corresponding parts.

The motions to be effected are, first, moving the gripers forward relatively to the cylinder and opening them; second, moving them back against the rest and closing them upon the paper; and, third, moving them forward with the cylinder again, which, of course, may be accomplished in various ways.

"The plan which I have adopted in this example is as follows: The upper griper, con sisting of the fingers a, rigidly connected to a shaft, 12, and the lower griper, consisting of a single bar, 0, is pivoted on it.

mounted in the outer ends of the rock-levers 0, so as not to revolve on its axis. The rock levers are pivot-ed, at f, upon the cylinder 9,

The shaft is.

'ward and close them when and the inner ends have a stud-pin, h, to be acted on by stationary cams t, which are to cause the gripers to swing forward relatively to the cylinder, both for opening them to release the printed sheet and to be ready for taking the blank sheet to be printed; also, for gaining time to move backward to the table and have a period of rest while taking the sheet. j represents springs, connected at one end to the cylinder and at the other end to the rock-levers, to pull the gripers back when the stud-pins arrive at the depressions lin the cams immediately after the gripers pass beyond the table It and the sheet of pa per, which projects sufficiently beyond the table to be caught 'by the gripers when they fly back against the stops g. m represents rods or bars pivoted to the cylinder at one end alongside of the rock-levers, but a little behind their pivots, and at the other end-s connected to the' lower griper by a longitudinal slot, at, in them, and-a pin, 0, on the griper, with a spring, 1), under the pins adjusted to push the griper 0 toward the upper gripers at. These bars open the gripers when they swing forthey swing back in consequence of swinging on centers eccentric to the centers on which the rock-levers swing. The object of the slots and the springs is to employ springs for closing the gripers by yielding pressure instead of the positive action that would be caused if the stud-pins 0 were connected to the bars so as not to move along them, because the springs will prevent any lost motion or looseness that might be caused by wear, and they can be readily adjusted to regulate the amount of pressure; but, while this arrangement is preferable, it is not absolutely essential, because good results may be had withthe rods m connected positively to the griper 0. q represents the stop-guides attached to the table or to the frame for arresting the gripers when pulled back by the springs j to take the paper, against which the ends of the shaft I) strike, or it may be the rock-levers e, if preferred. These stop-guides are so arranged relatively to the table as to arrest the gripers at the right point for taking the paper, and the rods m are so adjusted as not to allow the nippers to close wholly un-' til after moving back and being so arrested, so that the final closing will be accomplished while the gripers rest on the stops by the continued backward motion of the gripers relatively to the cylinder due to the forward motion of the latter in coming up with the gripers again, which, in flying back by the springs j, are stopped short of their ultimate movement backward for being kept open to receive the edge of the paper between them,

and then being closed on the paper while resting against the stops. After the gripers are closed in this way and are ready to take the paper forward, they are set in motion, together with the cylinder, again by the stops or projectionsc on the cylinder coming against the rock-levers;

but in order to lessen the 1 stops,

shock of their coming together, which would be very great on a press running very fast, the air-sprin gs represented by the cylinders a and pistons b are employed to begin the forward movement of the gripers by the compression of the air behind the pistons, which are connected to levers, as shown, and start the levers away from the stops q with a gradual and easy action, and let them fall back by the escape of the air, and be caught up by the stops c on the cylinder, which thus come up and finally set them going at the same speed as that of the cylinder-noiselessly and without shocks or jars. This may also be done, though not as well, by the cams i, constructed with a little rise at 10, against which the pins it come just before the stops 0 strike the rocklevers and throw the gripers forward slightly, but not as fast as the stops come toward them, which greatly lessens the force of the contact and softens the shocks.

The adjustment of the cam t and rock-levers is such thatwhen the gripers move forward they also swing downward slightly within or below the periphery of the cylinder, so as to pass under the table and the paper; but when they fly back they rise high enough for the upper gripers to pass above the paper.

. The cam t is so constructed that it begins to throw the gripers forward when they arrive at the point in the revolution of the cylinder where. it is desirable to have them open for releasing the printed sheet, so that it effects the releasing of the printed sheets also.

Any other part of the cylinder comingagainst any other part of the gripers or their supports may serve as well for setting the gripers in motion again as the stops '0, which I have described for the purpose.

Any other spring, or compound arrangement of sprin gs, may be used instead of spring j, and the construction and arrangement of the gripers and other details may be modified, as may be found necessary or desirable in practice.

Having thus described my invention, Iclaim as new and desire to secure by Letters Patent-= 1. The combination, with a continuously-revolving cylinder printing-press, of gripers having a period of rest relatively to the rotation of the cylinder While closing upon the paper, substantially as specified.

2. The combination, with a continuously-revolving cylinder-press, of gripers having an advance movement and a retrograde movement relatively to the cylinder preparatory to taking the paper, and a period of rest while taking it, substantially as specified.

3. The combination, with the table and the cylinder of a continuously-revolving printingpress, of movable gripers, stationary gage-stopstherefor, and springs or other equivalent instrumentalities, in such manner that the gripers are controlled relatively to the table and the paper while taking it by the said gagesubstantially as specified.-

4. The combination, with the cylinder of a continuously-revolving cylinder-press, of gripers having a period of rest While taking the paper, and a preparatory advance motion after taking it and before their motion with the cylinder is completely established, substantially as specified.

5. The combination, with the gripers and the rock-levers e, of the connecting-rods m pivoted to the cylinder eceentrically to the rock-levers, and'either having the' slotted holes and springs or not, substantially as specified.

6. The combination of the rock-levers e, stationary cams i, springs j, gripers, and the cylinder, substantially as specified.

7. The arrangement of the cams relatively Witnesses:

A. P. THAYER,

ALEX. F. ROBERTS. 

